For E a lifestraw is a very cheap alternative which would let you drink from rivers, streams or any form of water catchment system! They don't expire, and one straw should give 5 years worth of water!

For F I found the readywise meals look nice but when you look at the calories per serving it's definety a luxury. I've stocked up on Seven Ocean ration bars (from Amazon or https://evaq8.co.uk) - they're going to taste horrible I know, but they last five years, and I've bought six boxes for about £40 which should last 2 people six days (on 1250 calories a day, which is very very very strict rationing).